Two-battery LiFePo4 system?

Maine Sail · Apr 29, 2022

Johann said:
Well I just read about 50 posts after searching “Lithionics” in the FB group. I am shocked at the low level of effort Winnebago put into integrating LFP batteries in the Ekko and training their employees. They retained a battery meter set for Lead batteries that would indicate 100% until the Lithionics went into Reserve Voltage Cutoff. Many posts about this…. Just losing power in the night with 100% on the Ekko battery meter. Then being told by the dealer that the battery is bad and needed to be replaced!!!! What??!!

Then several improperly programmed or failed Balmars, Zamp controllers, Xantrex inverters… what’s going on over there? One guy says his Lithionics battery had an internal short that was corrected by a firmware update… Really?? Probably just at RVC like the others and the dealer called it a short (He did smell something electrical, but that could be anything), but hey, it’s got new firmware now so all is good. There are several reports of unbalanced charge/discharge in parallel, but is that the batteries or the installation?

There is one guy whose batteries went to sleep after a long period of non-use. At around 50% SOC. That is strange and not in the manual…

Anyway thanks for the link to the group, but it looks to me like Winnebago issues, not Lithionics.
EDIT: Found one post with a legit faulty BMS, AND one with Bluetooth failure.

I too am in the EKKO GROUP group. I joined because an owner emailed us about a programing issues with a Balmar regulator..On his particular installation there were numerous wiring mistakes with the regulator, it was programmed to a factory setting which is not correct for the Lithionics batteries.It aldo shipped from the factory without an alternator temperature sensor. It is really no different than the EcoTrek issues.The RVmanufacturers do not always follow that the battery makers instructions.We have a customer who has been using one of the Ecotrek batteries in his boat for five years now. the RV dealer deemed it junk and through it in the scrap pile.When my customer enquired about it the dealer said sure take it is junk.the battery was fine, the manufacturer had just wired it incorrectly.

Johann · Apr 30, 2022

jviss said:
I joined the FaceBook group "LiFePo4 Drop-In Batteries for boats

Seems pretty active. This is my most recent reply to my post there asking the question:

I'm still on the fence. I've raised my sights to 200Ah, and am thinking of two Victron 12.8V 100Ah Smart LFP's (BAT512110610). I would get a small AGM for the start battery. , the Smart 12/200 BMS (BMS210055000) and the Smart BatteryProtect 12/24-220 (BPR122022000). I would keep the Freedom 10 (I think now it's a 10, not a 20), and just program it for 90A max charging current, 14..2 Absorb and 13.2 Float. I've found that mine is pretty accurate, but I don't know if it's accurate enough for LFP. The issue with B2B chargers is I can't find on that will charge at 90A. BTW, I chose 90A because that's the closest increment to 100A with that BMS, which is specifically designed for an alternator connected to a LA start battery; the current is set by the fuse which doubles as a shunt.

Thats a good group. I love Victron stuff, especially all the info available to DIYers. But sometimes their literature makes it sound easier or more functional than it is (IMHO). I‘d also join the Victron FB group to ask any Victron specific questions. Then when you have firmed up your plan, post a diagram and you will get feedback on any pitfalls or limitations.

Victron Energy User Group (English) | Facebook

Stu Jackson · Apr 30, 2022

jviss said:
I would keep the Freedom 10 (I think now it's a 10, not a 20), and just program it for 90A max charging current, 14..2 Absorb and 13.2 Float.

IIRC, the charge rates for Freedom I/Cs are
Freedom 10 - 50 amps
Freedom 15 - 75 amps (this is the one I have)
Freedom 20 - 100 amps

As far as I know, one cannot limit the maximum charge rate of a Freedom I/C. The charger will provide its maximum charge rate whenever the battery acceptance allows it to do so, i.e.,whenever the system voltage remains below the target voltage. I also understand that the older Freedom units charging voltages could only be changed in a very narrow band based on battery temperature and gel or wet cell. This is from my 1998 Freedom 15 manual. Either the dip switches on the remote panel or a Link 2000, which gives you a wider ranges of voltage choices than the remote panel does. In either case you'd have to match the absorb and float, 'cuz they work together off the set batt temp, based on the table in the Link manual.

I would be interested to learn how, or if, one can actually limit the charge rate. Perhaps it is for the newer Freedom units than my 1998 unit, which is the one that came with the 2/0 wires already connected to the unit. Newer ones had the echo charger installed and required you to provide your own output wires to the bank. I'm also willing to learn something new. I also haven't re-read the entire Freedom manual this morning just read the voltage settings part. My unit has been in operation for over 20 years.

Stu Jackson · Apr 30, 2022

jviss said:
So maybe it's not so much a Freedom 20 thing as a Xantrex regulator and Link 2000-R thing.

Yes, that sounds correct.
From my Electrical Systems 101:

DISCONTINUED XANTREX PRODUCTS LINK

Discontinued Power Inverter/Chargers

and for Link products:

Discontinued Power Accessories

Davidasailor26 · Apr 30, 2022

jviss said:
By the way, on Xantrex documentation - I know I changed the ACCEPT voltage on my system to 14.8V, per Trojan's recommended acceptance voltage, but do you thinik I can find how to do that on any online-available manual? No! So frustrating! I know it's in the paper manual on the boat. Any help?

Looks like the battery selection steps are on page 9 of https://www.xantrex.com/documents/Discontinued-Products/FreedomMarineOwnersManual.pdf, and the battery type will result in the voltages on page 20.